People often have trouble performing 2 relatively simple tasks concurrently. The causes of this interference and its implications for the nature of attentional limitations have been controversial for 40 years, but recent experimental findings are beginning to provide some answers. Studies of the psychological refractory period effect indicate a stubborn bottleneck encompassing the process of choosing actions and probably memory retrieval generally, together with certain other cognitive operations. Other limitations associated with task preparation, sensory-perceptual processes, and timing can generate additional and distinct forms of interference. These conclusions challenge widely accepted ideas about attentional resources and probe reaction time methodologies. They also suggest new ways of thinking about continuous dual-task performance, effects of extraneous stimulation (e.g.. stop signals), and automaticity. Implications for higher mental processes are discussed. For more than 100 years, psychologists have been interested in people's ability (or inability) to perform two or more activities concurrently. One reason these limitations provoke curiosity is simply that people wonder what is humanly possible. This question has obvious significance for practical problems such

& Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in response preparation. The specific contribution of parietal and frontal areas to motor preparation has been explored in electrophysiological studies in monkey. However, the asso-ciative nature of sensorimotor tasks calls for the additional contributions of other cortical regions. In this article, we have investigated the functional anatomy of movement represen-tations in the context of an associative visuomotor task with instructed delays. Neural correlates of movement representa-tions have been assessed by isolating preparatory activity that

Abstract. The penalty kick plays a decisive role in the outcome of many Association Football (soccer) matches, and it is important for the kicker to choose the best strategy to score. This paper looked at the keeper-dependent strategy in which the kicker reacts to the goalkeeper's movement, and determined the amount of time needed before foot-ball contact for a player to successfully adjust their kicking direction. Field tests were conducted with 8 participants using lights to simulate the time and direction of a keeper's dive. A second experiment involving 6 participants determined simple, choice and discriminative reaction times for leg movements. It was found that the critical time needed to react and shoot the ball to the opposite side of the keeper was approximately 0.3 seconds. For three different strategies, involving different initial shooting directions, chance performance was found when stimuli were presented 300-400 ms before contact and full success rate was achieved when more than 500 ms were available. There were no significant differences between the strategies with regard to success. A large part of the pre-contact time was needed for reacting to the stimulus, and the time in which the adjustment could be made was approximately 135 ms.

Distraction from multiple in-vehicle secondary tasks: vehicle performance and mental workload implications

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The effect of stimulus interval and foreperiod duration on

Complex pattern perception and choice reaction time among